I would hope and assume that the community rules of HN don’t look kindly upon advocating the murder of any specific individuals.
That aside, I think it’s naive to assume that your proposed action would have a relevant outcome. Any successor is going to need to travel between facilities just as much — if not moreso — as they are brought up to speed and need to have ongoing meetings with executives and managers across a dozen locations.
Not to mention the travel involved in post-death matters of funerals, media coverage, high profile criminal investigations, and so on. And of course the wealth of one person then gets inherited by perhaps a dozen people, any of whom might live a more lavish (i.e. carbon intensive) lifestyle when they inherit even a small fraction of such enormous wealth.
Quite frankly I don’t see how your proposal has any chance of being remotely carbon positive.